1. Field of the Invention
This invention relates to an exhaust ventilator having a plate-shaped butterfly valve that is mounted on a frame to open and shut off a vent port formed on the frame. Particularly, it relates to an exhaust ventilator disposed on an automobile and having an improvement in a structure at an exit or outlet port for enabling an air to be exhausted from a cabin to an outside of the automobile.
2. Description of the Related Art
As a conventional exhaust ventilator, a quarter ventilator is disposed on a lateral rear side of a rear bumper of an automobile. The quarter ventilator has a plate-shaped butterfly valve, which is mounted on a frame having a vent port. The quarter ventilator permits an outside air to be introduced into a cabin through an air vent of an instrument panel. Moreover, the introduced air passed through the cabin and is exhausted via the quarter ventilator.
FIG. 5 shows an automobile on which an exhaust ventilator is provided. FIG. 6 shows a main portion, partially cut away, of a conventional exhaust ventilator. FIG. 7 shows a section of the conventional exhaust ventilator. The conventional art is disclosed in Japanese Laid Open Patent Publication 9-24729.
Referring to FIGS. 5 to 7, an opening 12 is formed at a rear lateral part 11 of a body of an automobile 1. Specifically, the opening 12 is disposed at an inside of a rear bumper 2 as shown in FIG. 5. An exhaust ventilator is provided in such opening.
A conventional exhaust ventilator has a main frame 113 that has a shape of short square pipe and that defines an outline of an overall structure of the exhaust ventilator. A flange 114 is formed at an outer end of the main frame 113. The flange 114 has a square ring shape that extends in a radially outward direction. The flange 114 has holes for inserting screws 115 so that it is fixed on the body lateral part 11 of the automobile 1 by the screws 115.
The main frame 113 has four inside surfaces: an inside upper surface 113a, inside lower surface 113b, inside left surface (not shown) and inside right surface 113d. The conventional exhaust ventilator has an upper partition 116a and lower partition 116b. The upper partition 116a and lower partition 116b are parallel to the upper surface 113a and lower surface 113b, respectively, and divide a space between the upper and lower surfaces 113a and 113b at equal intervals. The exhaust ventilator further has a left partition (not shown) and a right partition 116d. The left partition and right partition 116d are parallel to the left surface and a right surface 113d, respectively, and divide a space between the left and right surfaces 113d at equal intervals. The upper partition 116a, lower partition 116b, left partition and right partition 116d are crossed to each other. Thus, nine air vents 130 are formed. The air vents 130 have an equal opening area.
Moreover, the outer end surfaces 116A of the partitions 116a, 116b, 116d are protruded longer toward an outside one by one as they go down. The outer end surfaces 116A are positioned on an imaginary line Z shown by one-dot-chain line in FIG. 6, which is inclined at an angle xcex1=60 degrees.
A butterfly valve 118 has an upper side secured to an inside stepped part of the upper surface 113a of the main frame 113 so that it closes the corresponding air vents 130. Similarly, butterfly valves 118 have upper sides secured to lower half part of outer end surfaces 116A of the upper and lower partitions 116a and 116b, respectively, so that they close the corresponding air vents 130. The butterfly valves 118 are fixed by screws 120 via pressure pieces 119. Each of the butterfly valves 118 has its lower side tiltable. The pressure piece 119 has such rigidity that it uniformly transmits a pressure from the screw 120 to each butterfly valve 118. Moreover, the pressure piece 119 has a vertical surface and an inclined surface. A head of the screw 120 is disposed on the vertical surface, and the inclined surface is in close contact with the outer end surface 116a. Thus, the pressure of the screws 120 is evenly transferred to the outer end surface 116a. The butterfly valve 118 is formed of a flexible material composed of EPDM such as a solid rubber sheet having a predetermined mass.
As mentioned above, the butterfly valves 118 are disposed over the air vents 130, respectively. The outer end surfaces 116A of the left and right partitions 116d are aligned on the imaginary line Z. The main frame 113 has inside stepped surfaces on the inside left surface and inside right surface 113d, respectively. Such stepped surfaces are disposed on the imaginary line Z of the angle xcex1=60 degrees. Thereby, each butterfly valve 118 has its inside surface planarly contacted with the end surfaces 116A of the left and right partitions 116d and the stepped surfaces of the left and right surfaces 113d when the air in the cabin is not ventilated. Moreover, the main frame 113 has an inside stepped surface on the upper surface 113a. Such stepped surface is disposed on the imaginary line Z of the angle xcex1. The entire outer end surface 116A of the lower surface 113a is disposed on the imaginary line Z of the angle xcex1=60 degrees. Thereby, each butterfly valve 118 has its inside surface planarly contacted with the entire outer end surface 116A of the lower surface 113b when the air in the cabin is not ventilated. Moreover, the air in the cabin flows out of gaps formed between them or through the air vents 130.
The conventional exhaust ventilator constructed as above operates as follows.
When ventilation is necessary in the cabin of the automobile 1, an outside air is introduced into the cabin, for example, via an instrument panel. Then, an air pressure in the cabin increases. Accordingly, each butterfly valve 118 on each air vent 130 has its lower end moved outward, thereby forming a fixed gap. Thus, the inside air is exhausted to the outside through between the inside surfaces of the butterfly valves 118, the upper partition 116a, lower partition 116b and lower surface 113a of the main frame 113. At this time, the butterfly valve 118 opens in such a degree as to balance with the inside air pressure. When the inside air is not ventilated, the butterfly valve 118 closes each air vent 130 by its dead weight.
Consequently, even if the outside air pressure of the automobile 1 heightens, the butterfly valve 118 is never opened. Moreover, if a water pressure is applied from the outside when washing the car, the butterfly valve 118 keeps its closing state. Furthermore, since the water attached to an outside surface of the butterfly valve 118 can flow downward, the water during car wash never flows into the cabin.
To the contrary, the butterfly valve 118 maintains the closing state not by pressure by its elastic force but only by the dead weight. Therefore, there is no change in its elastic modulus by aged deterioration, so that it can operate stably. As a result, pressure loss due to the butterfly valve 118 decreases at the air vent 130, thereby enabling ventilation of the inside air with a little pressure difference.
However, when recycling as resource, the conventional exhaust ventilator needs to be disassembled into each part and classified into each material. Namely, it must have all the parts divided: the screws 115 at the flange 114, main frame 113, butterfly valve 118 of EPDM, pressure piece 119 and metal screws 120.
An object of the present invention is to provide an exhaust ventilator that has all parts made of a same material so as to enable recycle of resource, while keeping or improving its property.
According to a first aspect of the invention, an exhaust ventilator is provided. The exhaust ventilator has a frame. The frame has an opening for ventilating an air in a cabin of an automobile. A partition divides the opening of the frame into a plurality of air vents so as to separate an airflow in the cabin through the air vents. A butterfly valve of a plate shape has an upper end fixed to the partition so that a lower side of the butterfly valve is able to open and close the air vents. The frame, partition and butterfly valve are made of an olefinic thermoplastic material.
With such features, the frame, partition and butterfly valve can be integrally recycled without disassembling them. Thus, the inventive exhaust ventilator is preferable to recycling. Particularly, the butterfly valve of olefinic thermoplastic material exhibits excellent advantageous effects, even if airflow is small from the inside to the outside of a cabin.
An exhaust ventilator may further has a sealant for joining the frame to a body of the automobile. The sealant is made of an olefinic thermoplastic material.
The partition may divide the opening of the frame vertically and horizontally so as to arrange the air vents in a matrix manner. Each of the air vents has an aspect ratio of 1 to 1xc2x10.5.
Each of the air vents may have an opening area of 15 to 20 cm2.
The partition may have a lower portion protruded longer toward an outside than an upper portion so that an imaginary line connecting the upper portion and the lower portion extends at an angle of 50 to 70 degrees in relation to a horizontal plane and so that the butterfly valve also extends at an angle of 50 to 70 degrees in relation to a horizontal plane.
The butterfly valve may be fitted to the frame by a thermally deformed caulk. The caulk is made of an olefinic thermoplastic material.
The olefinic thermoplastic material may be selected from the group consisting of an olefinic thermoplastic elastomer, a styrene thermoplastic elastomer and a mixed material of an olefinic thermoplastic elastomer and a styrene thermoplastic elastomer.
Further objects and advantages of the invention will be apparent from the following description, reference being had to the accompanying drawings, wherein preferred embodiments of the invention are clearly shown.